During an election for city council, you hear a candidate say that 68% of children in the city live in poverty. You know that your children’s school has about 1

Question

Based on the candidate’s statement, about how many children in the school live in poverty?


Is the answer an estimate or calculation?

Answer 1

Dear Kristina,

 

I think there is something missing in the question. There should be something like "You know that your children's school has about 100 students enrolled." or something like that.

 

If we assume the school has 100 students, and we have information that 68% of children in the city live in poverty, then assuming that these children are evenly distributed across the city, and that the same percentage occurs among the children in the schools, and that they are evenly distributed among the schools, then 68% of the children at your school will live in poverty.

 

If there are 100 students, 68% is 68 students. If there are 150 students, 68% is  0.68 * 150 = 102. Whatever your total number of students at the school is, multiply by 0.68 to get the expected number of children living in poverty.

 

While we are calculating this answer, you'll notice in the paragraph "If we assume..." that there were a whole string of assumptions about how students living in poverty were distributed across the city. Because we are making assumptions, as is common in statistics when we are making predictions (actually, they are inferences, and we are using 'inferential statistics'), even if the basic information (the 68%) is accurate, the assumptions we are using to make the inferences are turning this into an estimate.

 

If we were to go and count the number of children living in poverty at your school, we may happen to get the number we calculated, but that would be chance. We might expect to get somewhere near that number, say +/- 10% (depending on the quality of the 68% value).

 

But your school may be in an area that is more or less well-off than average, and we don't know this information, so we are estimating.

 

Note that we are not completely ignorant here. It's not that we know nothing about the levels of poverty. We just don't know it perfectly. So we make an estimate. We have used the information we have (the 68%) to reduce the level of ignorance we have about the question of poverty. So we are somewhere between knowing nothing and having exact knowledge. Hence, we are estimating.

 

I hope that helps.